Occular motility

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Occular motility

  1. 1. OCULAR MOTILITY DEPARTMENT OF OPHTHALMOLOGY FATIMA COLLEGE OF MEDICINE
  2. 2. Introduction • Under normal conditions, the image of the object of regard falls simultaneously on the fovea of each eye, when the eyes are in perfect alignment. Any deviation from perfect ocular alignment is known as “STRABISMUS.”
  3. 3. Recti Muscles
  4. 4. Oblique Muscles
  5. 5. Yoke Muscles
  6. 6. DUCTION • Monocular rotations with no consideration of the position of the other eye – Adduction : Inward rotation – Abduction : Outward rotation – Elevation or Supraduction : Upward rotation – Depression or Infraduction : Downward rotation
  7. 7. FUSION • Formation of one image from the two images seen simultaneously by the two eyes – Motor fusion (EOM control) – Sensory fusion (visual sensory integration of the brain)
  8. 8. HETEROPHORIA • Latent deviation of the eyes held straight by binocular vision – Esophoria : tendency to turn inward – Exophoria : tendency to turn outward – Hyperphoria : tendency to deviate upward – Hypophoria : tendency to deviate downward
  9. 9. Heterotropia/Strabismus • Manifest deviation of the eyes that can not be controlled by binocular vision – Esotropia : convergent manifest deviation – Exotropia : divergent manifest deviation – Hypertropia : manifest deviation of one eye upward – Hypotopia : manifest deviation of one eye downward
  10. 10. Definition of Other Terms • Orthophoria : absence of any tendency of either eye to deviate when fusion is suspended • Primary deviation : deviation measured with the normal eye fixating and the eye with the paretic muscle deviating • Secondary deviation : deviation measured with the paretic eye fixing and the normal eye deviating
  11. 11. Definition of Terms • Prism Diopter - a unit of angular measurement used to characterize ocular deviations • Torsion : rotation of the eye about its anteroposterior axis – Intorsion : 12 o clock meridian turning toward the midline – Extorsion : 12 o clock meridian turning away from the midline
  12. 12. Definition of Terms • Conjugate Movement : Movement of the two eyes in the same direction at the same time • Vergences : Movement of two eyes in opposite directions – Convergence : The eyes turn inwards – Divergence : The eyes turn outwards
  13. 13. Synergistic and Antagonistic EOMS • Sherrington’s Law - There is a reciprocal innervation of antagonistic muscles. – The antagonist relaxes as the agonist contracts • eg. The right eye’s right gaze would involve a contraction of the right lateral rectus and a relaxation of the right medial rectus
  14. 14. YOKE MUSCLES • Hering’s Law : for movements of both eyes in the same direction, the corresponding agonist muscles receive equal innervation – e.g. When gazing right the right lateral rectus contracts along with the left medial rectus
  15. 15. Definition • Concomitant Strabismus : the degree of deviation is equal in all fields of gaze • Incomitant (paretic) Strabismus : the degree of deviation is unequal in different fields of gaze
  16. 16. Concomitant Strabismus
  17. 17. Incomitant Strabismus
  18. 18. Overshoot in Incomitant Esotropia
  19. 19. Amblyopia • Vision loss without any organic or anatomic ocular pathology – Strabismic – Refractive – Deprivation
  20. 20. Sensory Changes in Strabismus • Diplopia • Suppression • Amblyopia • Anomalous Retinal Correspondence • Eccentric Fixation
  21. 21. History • Family History • Age at Onset • Type of Onset (gradual, sudden, intermittent) • Type of Deviation (comitant or incomitant) • Fixation (one eye or alternating)
  22. 22. EOM Function
  23. 23. Ocular Examination • Visual acuity adapted for age • Determination of Refractive Error • Inspection
  24. 24. E Chart
  25. 25. Picture Chart
  26. 26. Leukocoria
  27. 27. Exotropia
  28. 28. Esotropia
  29. 29. Examination Specific for Ocular Motility • Cover Test • Uncover Test • Alternate Cover Test • Prism plus Cover Test • Maddox Rod Test • Hirschberg Test • Krimsky Test • Gaze Positions • Convergence Measurement
  30. 30. Cover Test
  31. 31. Cover Test
  32. 32. Cover-Uncover Test
  33. 33. Latent Exophoria
  34. 34. Hirschberg Test
  35. 35. Hirschberg’s Test
  36. 36. Krimsky Test
  37. 37. Patient’s View in Maddox Rod Testing
  38. 38. Treatment of Amblyopia • Occlusion Therapy • Refraction • Orthoptic Exercises
  39. 39. Surgical Management of Strabismus • Resection - strengthening procedure • Recession - weakening procedure
  40. 40. Squint Surgery
  41. 41. Thank You

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